The process in accordance with the preamble of patent claim 1 is known. It is used especially for the production of automotive metallic finishes (cf. for example U.S. Pat. No. 3,639,147, DE-A-3,333,072 and EP-A-38,127).
On economic and ecological grounds it is desirable to employ aqueous topcoat compositions in stage (3) of the basecoat-clearcoat process described above.
The topcoat compositions must be sprayable with the aid of automatic painting equipment. For this purpose their solids content must be high enough at spraying viscosity to furnish paint films of adequate film thickness with one to two cross-passes of the spray-gun and they must furnish baked paint films of good appearance (good flow-out, high gloss, good topcoat condition . . . ).
The aqueous topcoat composition disclosed in Example 2 of EP-A-38,127 does not meet all of the above requirements.
The object forming the basis of the present invention consists in the preparation of aqueous topcoat compositions which meet the above requirements.